@stefan so, let's flip this idea around. With hundreds of millions of users each, Threads and Flipboard represent the vast majority of Fediverse users. The rest of us are a rounding error in that calculation.
Maintaining a connection to that big network is not guaranteed. There's no reason a group of ActivityPub implementers couldn't go to allowlist mode and just federate with the handful of services that make up the majority of user accounts on the network.